Ring management system

ABSTRACT

A production system capable of further improving production efficiency and quality. The ring management system includes size measurement unit for measuring size of the ring, first convey unit for moving the ring w whose size has been measured, a first stocker having a plurality of storage positions for storing rings conveyed by the first convey unit, a second convey unit for conveying out the rings from the first stocker means for stacking, and a control unit. The control unit includes memory means for storing the rings size measured by the size measurement means in association with the storage position in the first stocker, first selection means for selecting a ring constituting a stacked ring according to the ring size stored in the memory means, and first instruction means to instruct the second convey unit to convey out the ring selected by the first selection means from the storage position pj in the first stocker.

This application is a Divisional of co-pending application Ser. No.10/475,143, filed on Nov. 23, 2003, and for which priority is claimedunder 35 U.S.C. § 120. Application Ser. No. 10/475,143 is the nationalphase of PCT International Application No. PCT/JP02/02247 filed on Mar.11, 2002 under 35 U.S.C. § 371, which also claims priority toApplication No. 2001-122208 filed in Japan on Apr. 20, 2001, ApplicationNo. 2001-167296 filed in Japan on Jun. 1, 2001, Application No.2001-167297 filed in Japan on Jun. 1, 2001, and Application No.2001-194668 filed in Japan on Jun. 27, 2001 under 35 U.S.C. § 119. Theentire contents of each of the above-identified applications are herebyincorporated by reference.

TECHNICAL FIELD

The present invention relates to a ring management system for aplurality of rings having elasticity in the radius direction for layeredring configuration.

BACKGROUND ART

A non-stage speed change gear (CVT) belt used for a speed change gear inan automobile and the like includes a plurality of endless metal rings(hereinafter, referred to simply as “rings”) layered in the thicknessdirection. Each ring is manufactured to have a different circumferentiallength and thickness preset according to its layer. These rings areselected, combined, and produced into a layered ring.

Each of the rings is produced so as to satisfy the size of each layerbut actual size may be slightly different from the set values.Combination of such rings may not produce a layered ring of highquality.

Rings are firstly measured in size and then placed on a storage shelf orthe like. According to the measurement values, rings to be combined areselected. The selected rings are taken out of the storage shelf andlayered, thereby obtaining a layered ring of high quality.

Conventionally, measurement of the plurality of rings, storage of therings after the size measurements, selection of rings, and ring layeringhave been separately performed and each step or transition therebetweenhas been performed by a corresponding staff. Difference in quality ofthe staff work fluctuates production efficiency and quality of thelayered rings.

DISCLOSURE OF THE INVENTION

It is therefore an object of the present invention to provide a ringmanagement system capable of improving production efficiency and qualityof layered rings.

A ring management system according to a first embodiment of the presentinvention comprises size measurement means for measuring size of thering, first convey means for moving the ring whose size has beenmeasured by the size measurement means, first storage means having aplurality of storage positions for storing rings conveyed in by thefirst convey means, second convey means for conveying out the rings fromthe first storage means, and control means including memory means forstoring for each of the rings, size measured by the size measurementmeans in association with the storage position in the first storagemeans, first selection means for selecting a ring for constituting astacked ring according to the ring size stored in the memory means, andfirst instruction means to instruct the second convey means so as toconvey out the ring selected by the first selection means from thestorage position in the first storage means corresponding to the size ofthe ring stored by the memory means. According to this invention, thesize measurement means, the fist convey means, the first storage means,and the second convey means perform ring size measurement, convey forstorage, storage, and convey for stacking. This eliminates difference inwork quality of each working staff and can improve stacked ringproduction efficiency and quality.

Moreover, rings to constitute a stacked ring are selected by the firstselection means according to the size measured by the size measurementmeans. Then, a ring stored at a storage position in association with thering size stored by the memory means is conveyed out by the secondconvey means and stacked for a stacked ring. Thus, a plurality of ringsconstituting a most appropriate combination are selected and accuratelytaken out of the first storage means, thereby producing a high-qualitystacked ring.

Moreover, the ring management system according to the first embodimentfurther comprises third convey means for conveying rings out of thefirst storage means, and second storage means having a plurality ofstorage positions for storing rings conveyed in by the third conveymeans, wherein the control means further includes second selection meansfor selecting a ring whose storage time in the first storage meansreaches a predetermined time or more or having identical sizes at apredetermined number or more of places from rings being stored in thefirst storage means, and second instruction means for instructing thethird convey means to convey out the ring selected by the secondselection means from the storage position in the first storage meansstored in association with the ring storage time or size and convey itinto the second storage means.

According to this invention, it is possible to eliminate a situationthat the same ring is stored in the first storage means for a timeexceeding a predetermined time or too many rings having identical sizeare stored in the first storage means. Thus, it is possible to suppressreduction of the selection range of the convey-in position of the ringin the first storage means and eliminate stagnation of convey of thering into the first storage means.

Furthermore, the ring management system according to the firstembodiment of the present invention further comprises: fourth conveymeans for conveying rings from the second storage means, wherein thememory means stores for each of the rings, the size measured by the sizemeasurement means in association with the storage position in the secondstorage means, in case rings stored in the first storage means cannot beselected, the first selection means selects a ring from the rings storedin the second storage means so as to constitute a stacked ring, and thefist instruction means instructs the fourth convey means to convey outthe ring selected by the first selection means from the storage positionin the second storage means stored in association with the size of thering by the memory means.

According to the present invention, when it is impossible to select anappropriate ring to constitute a stacked ring from the first storagemeans, the ring is selected and conveyed out from the rings stored inthe second storage means.

Moreover, in the ring management system according to the firstembodiment of the present invention, the size measurement means, theconvey means, and the storage means include holding means for holding acircular ring in substantially elliptic shape.

According to the present invention, ring size is measured while a ringis maintained in the substantially elliptic shape and deformation in theradius direction of the ring by the restoration elasticity issuppressed. This increases the size measurement accuracy. Moreover,after the size measurement, the ring is conveyed and stored whilemaintaining the substantially elliptic shape. This eliminates thesituation that the ring in the substantially elliptic shape is deformedby its restoration elasticity in an unpredicted direction to contactwith and damage something or to be damaged itself. Furthermore, the ringis handled as “a substantially elliptic work having a constant width inthe short-axis direction” regardless of the difference in ring size.Accordingly, holding means handling this work have common specificationsin constituting the convey means and storage means, thereby enablingsubstitution and flexibililty.

In order to produce a high-quality stacked ring, it is necessary toselect appropriate rings to constitute the stacked ring and it isnecessary to accurately measure the circumferential length and thicknessof the rings as the selection condition.

To cope with this, the size measurement means includes a pair of rollersarranged with rotation shafts parallel to each other and theshaft-to-shaft distance can be changed, circumferential length measuringmeans for measuring the circumferential length of a ring through theshaft-to-shaft distance of the pair of rollers while driving to rotatethe ring hung over the pair of rollers and given a predetermined tensionby the increase of the shaft-to-shaft distance of the rollers, thicknessmeasurement means for measuring thickness of the ring hung over the pairof rollers and given a predetermined tension at an intermediate positionbetween the rollers.

In the size measurement means constituting the ring management system ofthe present invention, firstly, a ring is hung over a pair or rollersand the shaft-to-shaft distance of the rollers is increased to apply apredetermined tension to the ring. The ring is driven to rotate by thepair of rollers and the ring circumferential length is measuredaccording to the shaft-to-shaft distance of the pair of rollers.

Next, rotation of the pair of rollers is stopped and the ring thicknessis measured by the thickness measurement means while applying apredetermined tension to the ring. Thus, by measuring the thicknesswhile applying a predetermined tension to the ring, bending of the ringis prevented and it is possible to appropriately measure the thickness.Moreover, since it is possible to measure thickness of a plurality ofrings under the common condition, it is possible to obtain ringmeasurement data appropriately used when deciding stacking order of therings. Furthermore, it is possible to measure the ring circumferentiallength and ring thickness continuously with a high efficiency.

Moreover, the thickness measurement means includes a pair of contactsarranged at the inner circumferential side and the outer circumferentialside of a ring hung over the pair of rollers in such a manner that theycan advance/retrieve so as to be in abutment with each other, andcontact advance/retrieve means for bringing the contacts into abutmentwith the inner circumferential surface and the outer circumferentialsurface of the ring, and means for measuring the thickness of the ringhung over the pair of rollers by a displacement of a contact withrespect to the other contact.

According to the present invention, it is possible to measure a ringthickness only by measuring displacement of one of the contacts withrespect to the other contact. Thus, with a simple configuration, it ispossible to perform a highly accurate measurement.

Upon size measurement, thermal expansion or shrinkage may be caused inone or two of the rollers due to heat generated by driving of therollers or the ambient temperature. When the ring outer circumferentiallength is measured based on the shaft-to-shaft distance between therollers, there may be involved a large measurement error affected by thetemperature.

To cope with this, the ring management system further comprisestemperature measurement means for measuring temperature of at least oneof the rollers, and data correction means for correcting measurementdata obtained by the circumferential length measurement means and thethickness measurement means, according to the temperature measured bythe temperature measurement means.

According to the present invention, the measurement data obtained by thecircumferential measurement means and the thickness measurement meanswhich have been affected by thermal expansion or shrinkage caused in oneor two of the rollers due to heat generated by driving of the rollers orthe ambient temperature can be corrected according to the temperature ofat least one of the rollers. Accordingly, even when the temperature ofone of the rollers fluctuates and measurement values fluctuate becauseof the thermal expansion and shrinkage, it is always possible to obtainaccurate measurement data.

In order to reduce the convey space of a plurality of rings, a pluralityof rings aligned in the lateral direction (ring radius direction) arepreferably aligned in the vertical direction (ring axis direction). Inthis case, for example, after each ring is sandwiched by robot arms,robot arms can move vertically and horizontally. However, the robot armsrequire a comparatively large space for movement. Moreover, the ringconvey requires a comparatively long time, lowering the work efficiency.For this, aligning means requiring a small drive space and capable ofrapidly converting aligning direction of a plurality of rings isdesired.

To cope with this, the ring management system according to the firstembodiment of the present invention, further comprises aligning meansfor aligning in the perpendicular direction, a plurality of rings whichhave been measured in size and aligned in the horizontal directionbefore being conveyed into the first storage means by the first conveymeans, the aligning means including horizontal aligning means having aplurality of holding means for holding a plurality of rings arranged inthe horizontal direction, perpendicular aligning means having aplurality of holding means for holding a plurality of rings arranged inthe perpendicular direction, convey means for moving the perpendicularaligning means in the aligning direction of a plurality of rings by thehorizontal aligning means and lifting up so that the holding means ofthe perpendicular aligning means successively oppose to the holdingmeans of the horizontal aligning means, moving means for successivelymoving a plurality of rings held by the holding means of the horizontalaligning means onto the holding means of the perpendicular aligningmeans in synchronization with the movement of the perpendicular aligningmeans by the convey means, and convey-out means for conveying out theplurality of rings held by the holding means of the perpendicularaligning means while maintaining the arrangement in the perpendiculardirection.

According to this invention, firstly, rings aligned in the horizontaldirection by the horizontal aligning means are successively moved ontothe holding means of the perpendicular aligning means which graduallyrises up while moved in the lateral direction by the moving means. Thus,the plurality of rings which have been aligned in the horizontaldirection are aligned in the perpendicular direction by theperpendicular aligning means. Thus, aligning of a plurality of rings caneasily be converted from the horizontal direction to the perpendiculardirection.

Moreover, the ring management system according to the first embodimentof the present invention further comprises perpendicular aligning meansfor aligning in the perpendicular direction a plurality of rings alignedin the horizontal direction before being conveyed into the first storagemeans by the first convey means after the size measurement by the sizemeasurement means, the aligning means including a plurality of holdingmeans arranged in the horizontal direction for holding a plurality ofrings, moving means for successively moving one holding meansimmediately below another holding means, so that the plurality ofholding means arranged in the horizontal direction are aligned in theperpendicular direction, and convey-out means for conveying out therings held by the plurality of holding means arranged in theperpendicular direction while maintaining the state aligned in theperpendicular direction.

According to the present invention, a plurality of rings are firstlyaligned in the horizontal direction by being held by a plurality ofholding means arranged in the horizontal direction. Then, the movingmeans moves one of the holding means immediately below another holdingmeans and thus successively moves the holding means, thereby arrangingthe plurality of holding means in the perpendicular direction. Thus, theplurality of rings aligned in the perpendicular direction. That is,moving of the holding means can rapidly converts the ring alignmentdirection, thereby improving work efficiency.

Moreover, the convey means includes a slider for moving one holdingmeans toward another holding means, a support member which can be liftedup and down along a guide rod extending from the slider and havingholding means at the upper portion thereof, urging means for urging thesupport member upward, an inclined portion provided on the supportmember and is gradually inclined downward toward the other holdingmeans, and a cam roller for pressing the support member against theurging force by the urging means via the inclined portions as the slidermoves, so as to guide one holding means immediately below the otherholding means.

According to the present invention, only by moving a holding means atthe upstream side by the slider toward the holding means at thedownstream side, the inclined portion and the cam roller are broughtinto sliding abutment, so as to lower the holding means of the upstreamside via the support member. Thus, it is possible to smoothly move theother holding means from the upstream side to immediately below theother holding means at the downstream side. This simplifies the systemconfiguration and rapidly converts the ring alignment direction.

In order to solve the aforementioned problems, a ring management systemaccording to a second embodiment of the present invention comprises sizemeasurement means for measuring size of a ring by hanging the circularring over a pair of rollers whose shaft-to-shaft distance can be changedso that the ring is in the substantially elliptic shape, first conveymeans for moving the ring removed from the pair of rollers, whilesandwiching the ring by sandwiching means so as to maintain thesubstantially elliptic shape of the ring which tends to return tocircular shape, first storage means having a plurality of storagepositions for storing rings conveyed in by the first convey means andreleased from the sandwiching means of the first convey means whileregulating the ring tending to return to a circular shape from thesubstantially elliptic shape in the short-axis direction with regulatingmeans, and second convey means for conveying out the rings from thefirst storage means by releasing the ring from the regulating means ofthe first storage means by sandwiching the ring and reducing thesandwiching interval while maintaining the substantially elliptic shapewith sandwiching means.

According to the present invention, ring size is measured while the ringis maintained in the substantially elliptic shape and deformation in theradius direction of the ring by the restoration elasticity issuppressed. Accordingly, it is possible to increase the size measurementaccuracy.

Moreover, after the size measurement, the ring is conveyed and storedwhile maintaining the substantially elliptic shape. Accordingly, it ispossible to prevent a situation that the ring in the substantiallyelliptic shape is deformed in an unexpected direction by its restorationelasticity to contact with and damage something or to be damaged itself.

Furthermore, the ring is handled as “an substantially elliptic workhaving a constant width in the short-axis direction” regardless of thedifference in ring size. Accordingly, holding means handling this workhave common specifications in constituting the convey means and storagemeans, thereby enabling substitution and flexibility.

Moreover, the size measurement means, the first convey means, the firststorage means, and the second convey means perform a series ofprocedures including the ring size measurement, convey for storage,storage, and convey for stacking. This eliminates the difference of workcaused by different working staffs and can improve the stacked ringproduction efficiency and quality.

Moreover, the ring management system according to the second embodimentof the present invention further comprises third convey means forreleasing a ring stored in the substantially elliptic shape in the firststorage means, from the regulating means of the first storage means bysandwiching the ring and reducing the sandwiching interval withsandwiching means and conveying the ring while maintaining thesubstantially elliptic shape, and second storage means having aplurality of storage positions for storing rings and released from thesandwiching means of the third convey means while regulating the ringtending to return to a circular shape from the substantially ellipticshape in the short-axis direction with regulating means.

Furthermore, the ring management system according to the secondembodiment of the present invention further comprises fourth conveymeans for conveying out the rings from the second storage means byreleasing the ring from the regulating means of the second storage meansby sandwiching the ring and reducing the sandwiching interval whilemaintaining the substantially elliptic shape with sandwiching means.

Moreover, the ring management system according to the second embodimentof the present invention further comprises hanging means, wherein thecircular ring is sandwiched by sandwiching means so as to be in thesubstantially elliptic shape whose long-axis direction is matched withthe roller-from-roller departing direction of the size measurement meansand the ring is conveyed outside of this pair of rollers, and the sizemeasurement means releases the ring conveyed outside the rollers by thehanging means, from the sandwiching means of the hanging means byincreasing the shaft-to-shaft distance of the rollers, so that the ringis hung over the rollers.

Furthermore, the ring management system according to the secondembodiment of the present invention further comprises removal means forremoving the ring from the pair of rollers, which ring tends to returnto the circular shape from the substantially elliptic shape withreduction of the shaft-to-shaft distance of the pair of rollers of thesize measurement means, by sandwiching the ring in the short-axisdirection, so as to maintain the substantially elliptic shape.

Moreover, in the ring management system according to the secondembodiment of the present invention further comprises aligning means foraligning the rings in the horizontal direction while regulating thering, which tends to return to the circular shape from the substantiallyelliptic shape after being removed form the pair of rollers of the sizemeasurement means, in its short-axis direction and keeping itssubstantially elliptic shape with first regulating means, and conveyingthe ring after releasing the rings from the first regulating means bysandwiching the ring aligned in the horizontal direction in thesubstantially elliptic shape and reducing the sandwiching interval withsandwiching means, and aligning the rings in the horizontal directionwhile keeping their substantially elliptic shapes after releasing therings from the sandwiching means by regulating the ring, which tends toreturn to the circular shape from the substantially elliptic shape whenthe sandwiching interval of the sandwiching means is increased, in itsshort-axis direction with second regulating means, wherein the firstconvey means convey the ring while keeping its substantially ellipticshape, after releasing the rings, which have been aligned in thehorizontal direction by the aligning means, from the second regulatingmeans of the aligning means by sandwiching the rings and reducing thesandwiching interval with sandwiching means.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 explains a configuration of the ring management system accordingto an embodiment of the present invention.

FIG. 2 explains an essential portion of an induction unit.

FIG. 3 is a front view of a size measurement unit.

FIG. 4 is a side view of the size measurement unit.

FIG. 5 explains ring thickness measurement method in the sizemeasurement unit.

FIG. 6 and FIG. 7 explains configuration of an aligning unit.

FIG. 8 explains operation of the aligning unit.

FIG. 9 explains an essential portion of a first and a second conveyunit.

FIG. 10 explains configuration of the first and second convey units anda first stockeer.

FIG. 11 and FIG. 12 explain function of the ring management system.

FIG. 13 and FIG. 14 explain an aligning unit according to a secondembodiment.

FIG. 15 and FIG. 16 explain operation of the aligning unit according tothe second embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

Description will now be directed to a ring management system accordingto an embodiment of present invention with reference to the attacheddrawings. The ring management system shown in FIG. 1 includes: aconveyer belt 50; an induction unit 100; a size measurement unit 200; analigning unit 300; a first convey unit 400, a first stocker (firststorage means) 500; a second convey unit 600; a second stocker (secondstorage means) 700; a stacking unit 800; a conveyer belt 850; and acontrol unit 900.

The conveyer belt 50 conveys a plurality of rings w in the originalsubstantially elliptic shape in lateral direction (radius direction)(indicated by arrow 1 in FIG. 1).

As shown in FIG. 2, the induction unit 100 includes: a rail 102extending in the convey direction of the ring w; a frame 104 movablealong the rail 102; a pair of right and left sandwiching means 110movable together with the frame 104. The sandwiching means 110 includes:two pairs of claws 112 opposing to each other; a cylinder 116 forhorizontally moving the claws 112 via a rod 114 in a vertical directionagainst the opposing direction; and a rotary actuator 118 for rotatingthe cylinder 116 in a direction vertical to the axial direction. By theinduction unit 100, the ring w which tends to return to a substantiallycircular shape is regulated by the opposing two pairs of claws 112 andsandwiched in the substantially elliptic shape.

The induction unit 100 places the ring w conveyed by the conveyer belt50 on a pair of rollers 210 and 220 of the size measurement unit 200 assubstantially elliptic “hanger means” (arrow 2 in FIG. 1). Moreover, theinduction unit 100 removes the ring w from the pair of rollers 210 and220 as “removal means” while maintaining the substantially ellipticshape and transports it to the aligning unit 300 (arrow 3 in FIG. 1).

Now explanation will be given on the configuration of the sizemeasurement unit 200 with reference to FIG. 3 and FIG. 4.

The size measurement unit 200 as the “circumferential length measurementmeans” of the ring w includes: a drive roller 210; a follower roller 220placed below and in parallel to the drive roller 210; a firstdisplacement sensor 230 for outputting a signal according to adisplacement amount of the follower roller 220 in the perpendiculardirection; and calculation means 231 consisting of a CPU and the likemeasuring the circumferential length (inner circumferential length) l ofthe ring w according to the output signal from the first displacementsensor 230.

The drive roller 210 has its shaft supported via a bracket 212 by acolumn 204 extending from a basement 202. The drive roller 210 is drivento rotate by a drive motor 214 (drive means) provided at the back of thecolumn 204. The bracket 212 has an upper limit switch (not depicted).Above a bearing block 216 of the drive roller 210, there is provided atemperature sensor 218 for outputting a signal according to thetemperature of the drive roller 210 measured via the bearing block 216.

The follower roller 220 is shaft-supported by the bracket 222. Thebracket 222 is engaged with two rail members 206 vertically extending onthe column 204 via an engagement member 224 so as to be slidable alongthe rail members 206. Moreover, the bracket 222 is lifted up by acylinder 228 via a rod 226 connected to the lower portion thereof.Furthermore, the bracket 222 applies by its weight, tension to the ringw hung over pair of the rollers 210 and 220. The rail member 206 has alower limit switch 208 at a lower portion thereof.

The first displacement sensor 230 has expandable contact 232. Thecontact 232 is in abutment with the lower portion of the bracket 222 ona perpendicular line including the axial center of the drive roller 210and the axial center of the follower roller 220. The contact 232 isurged in the direction of the bracket by urging means (not depicted)such as a spring member and the tip end of the contact 232 is displacedtogether with the bracket 222.

Moreover, the size measurement unit 200 includes as the “thicknessmeasurement means” of the ring w: an inner contact 240 to oppose toinner circumferential surface of the ring w hung over both the rollers210 and 220 and an outer contact 250 to oppose to the outercircumferential surface of the ring w hung over both the rollers 210 and220; a second displacement sensor 260 for outputting a signal accordingto a displacement amount of the outer contact 250; and calculation means261 composed of a CPU or the like for measuring the thickness t of thering w according to the output signal from the second displacementsensor 260.

Inner contact 240 is horizontally driven by the cylinder 242. The outercontact 250 is horizontally driven by the second displacement sensor260.

The size measurement unit 200 measures the circumferential length of thering w hung over the pair of rollers 210 and 220 in the substantiallyelliptic shape according to displacement during rotation of the rollers210 and 220. Moreover, the size measurement unit 200 measures thethickness of the ring w hung over the pair of rollers 210 and 220 in thesubstantially elliptic shape. It should be noted that here the“circumferential length” of the ring w is a length along the innercircumferential length of the ring w, i.e., “inner circumferentiallength”.

Explanation will be given on configuration of the aligning unit 300 withreference to FIG. 6 and FIG. 7.

The aligning unit 300 includes first holding means 310 and secondholding means 320 as configuration of “horizontal aligning means”.Moreover, the aligning unit 300 includes perpendicular aligning means330. The perpendicular aligning means 330 has upper holding means 331and lower holding means 332 for aligning rings w in a perpendiculardirection.

Furthermore, the aligning unit 300 includes first moving means 340 andsecond moving means 350 for moving the ring w held by the first holdingmeans 310 and the second holding means 320 onto the upper holding means331 and the lower holding means 332 of the perpendicular aligning means330; and convey means 360 for conveying out a pair of rings w aligned ina perpendicular direction by the perpendicular aligning means 330.

The first holding means 310 and the second holding means 320respectively have plates 314 and 324 where the ring w is placed andregulating means 312 and 322 for regulating the ring w placed on theplates 314 and 324 from both sides into an substantially elliptic shape.

The first moving means 340 has a pair of arms 344 for sandwiching thering w in the substantially elliptic shape via a plurality of claws 342positioned between regulating means 312 of the first holding means 310.Moreover, the first moving means 340 includes a cylinder 346. By thiscylinder 346, advance/retrieval is performed with respect to theperpendicular aligning means 330 guided by the rail provided on a table301.

The second moving means 350, almost identically to the first movingmeans 340, includes a pair of arms 354 at a changeable distance forsandwiching the ring was in the substantially elliptic shape via aplurality of claws 352 positioned between the regulating means 322 ofthe second holding means 320. Moreover, the second moving means 350includes a cylinder 356. By this cylinder 356, advance/retrieval isperformed with respect to the perpendicular aligning means 330 guided bythe rail 358 provided on the table 301.

The upper holding means 331 and the lower holding means 332 of theperpendicular aligning means 330 respectively include regulating means333 and 334 for regulating the ring w into the substantially ellipticshape from both sides.

As the “convey means” for moving the perpendicular aligning means 330,there are provided a first inclined guide portion 335 inclinedleft-upward and a second inclined guide portion 336 in parallel to thefirst inclined guide portion 335 on an intermediate table 302. The firstinclined guide portion 335 has a first slider 337 moving along theinclination and the first slider 337 is connected to the perpendicularaligning means 330. The second inclined guide portion 336 has a secondslider 338 moving along the inclination and the second slider 338 isconnected to the first inclined guide portion 335.

The convey means 360 is composed of upper convey means and lower conveymeans 362. The upper convey means 361 and lower convey means 362 have apair of arms 364 at a changeable distance for sandwiching the ring w inthe substantially elliptic shape via a plurality of claws 363. Moreover,the convey means 360 has a cylinder 366. By this cylinder 366,advance/retrieval is performed with respect to the perpendicularaligning means 330 guided by the rail 368 provided on the table 301.

After the size measurement by the size measurement unit 200, thealigning unit 300 aligns the ring w (arrow 3 in FIG. 1) transported bythe induction unit 100, in the substantially elliptic shape in thelateral direction. Moreover, the aligning unit 300 vertically aligns therings w aligned in the lateral direction in the substantially ellipticshape.

As shown in FIG. 9A and FIG. 9B, the first convey unit 400 includesfirst sandwiching means 410 for sandwiching the ring w at a changeabledistance via the pair or arms 412 having a claw portions 414. Moreover,as shown in FIG. 10, the first convey unit 400 includes: firsthorizontal drive means 420 for horizontally driving the firstsandwiching means 410; first perpendicular drive means 430 forperpendicularly driving the first sandwiching means 410 and the firsthorizontal drive means 420 along a first columnar member 402 extendingoutside the outer circumference of the first stocker 500; and firstrotation means 440 for rotating the first columnar member 402 around itsaxis.

The first convey unit 400 transports the ring w from the aligning unit300 by sandwiching the ring w by the first sandwiching means 410 in thesubstantially elliptic shape (arrow 4 in FIG. 1). The first sandwichingmeans 410 is driven in the perpendicular direction and the horizontaldirection while sandwiching the ring w in its substantially ellipticshape and conveying into the first stocker 500 (arrow 5 in FIG. 1).

As shown in FIG. 10, the first stocker 500 is substantially cylindricaland has a plurality of storage chambers 502 partitioned in acircumferential direction and axial direction and having an open outercircumference. The first stocker 500 can be rotated around its axis bythe first rotation means 510. Each of the storage chambers 502 hasregulating means 504 (see FIG. 1) for regulating the ring w from bothsides so as to prevent returning to circular shape. The first stocker500 stores a plurality of rings w conveyed by the first convey unit 400while regulating the rings w by the regulating means 504 so as to be inthe substantially elliptic shape.

The second convey unit 600 has configuration identical to the firstconvey unit 400. The second convey unit 600 sandwiches the ring w by thesecond sandwiching means 610 and conveys the ring in the substantiallyelliptic shape from the first stocker (arrow 6 in FIG. 1). Moreover, thesecond convey unit 600, as the “third convey means” of the presentinvention sandwiches the ring w by the second sandwiching means 610 andconveys the rings in its substantially elliptic shape out of the firststocker 500 and conveys the rings into the second stocker 700 (arrow 6′in FIG. 1). Furthermore, the second convey unit 600 as the “fourthconvey means” of the present invention sandwiches the ring w by thesecond sandwiching means 610 and conveys the ring w in its substantiallyelliptic shape out of the second stocker 700 (arrow 6″ in FIG. 1). Thesecond convey means 600 temporarily stores the plurality of rings wconveyed out of the first stocker 500 or the second stocker 700according to the stacking order and transports them to the stacking unit800 (arrow 7 in FIG. 1).

The second stocker 700 has configuration almost identical to that of thefirst stocker 500. The second stocker 700 is rotated around its axis bythe second rotation means 710. Moreover, the second stocker 700 stores aplurality of rings w conveyed in by the second convey unit 600 whileregulating the rings w from both sides so as to maintain thesubstantially elliptic shape.

In the stacking unit 800, a plurality of rings w returned to thesubstantially circular shape are stacked to form a stacked rings R whichare transported to the conveyer belt 850 (arrow 8 in FIG. 1).

The conveyer belt 850 conveys the stacked rings R formed by the stackingunit 800 outside (arrow 9 in FIG. 1).

The control unit 900 is composed of a personal computer and a computerprogram for exhibiting various functions including the ring w managementis installed. The control unit 900 includes: a timer 906; memory means908; first selection means 910; first instruction means 912; secondselection means 920; and second instruction means 922.

The timer 906 measures storage time X of each of the rings w in thefirst stocker 500.

The memory means 908 stores for each of the rings w: a circumferentiallength l and thickness t, storage time τ measured by the timer 906, andstorage position in the first stocker 500 and the second stocker 700.

The first selection means 910 selects a ring w according to thecircumferential length l and the thickness t stored in memory means 908so as to obtain a most appropriate combination. The first instructionmeans 912 instructs the second convey unit 600 to transport the ring wselected by the first selection means 910 to the stacking unit 800 andgives various instructions to the respective units which will bedetailed later.

The second selection means 920 selects a ring w to be transported fromthe first stocker 500 to the second stocker 700 according to the storagetime τ and the size (l, t) of the ring w stored in the memory means 908.The second instruction means 922 instructs to transport the ring wselected by the second selection means 920 from the first stocker 500 tothe second stocker 700.

Explanation will be given on the function of this system having theaforementioned configuration with reference to FIG. 1 to FIG. 12. Onlymain signals and data transmitted and received between the units will beexplained below. However, other data and signals according to thecommunication protocol and the program language used in this system mayalso be transmitted and received.

Firstly, induction unit 100 sandwiches a substantially circular ring wconveyed by the conveyer belt 50, so as to be in the substantiallyelliptic shape. More specifically, the sandwiching means 110 is movedabove the conveyer belt 50 together with the frame 104 along the rail102 shown in FIG. 2. Moreover, the cylinder 116 is rotated by the rotaryactuator 118 so that the claw portion 112 is directed downward. Here,the ring w is pushed in the horizontal direction by the sandwichingmeans (not depicted) at the end portion of the conveyer belt 50, so asto have the substantially elliptic shape. The cylinder 116 lowers theclaw portion 112 to the position of the ring w via the rod 114. Here,the pushing by the sandwiching means at the end portion of the conveyerbelt 50 is released and the ring w tends to return to the circular shapebut is regulated by the claw portion 112 in the short-axis direction andsandwiched while maintaining the substantially elliptic shape. Moreover,since the claw portion 112 is lifted up by the cylinder 116, the ring wis lifted up from the conveyer belt 50 (dotted line in FIG. 2).

Next, the induction unit 100 sandwiching the ring w in the substantiallyelliptic shape by the sandwiching means is transported to the sizemeasurement unit 200 (arrow 1 in FIG. 1). More specifically, thesandwiching means 110 is moved together with the frame 104 along therail 102 shown in FIG. 2 up to a position opposing to the pair ofrollers 210 and 220 of the size measurement unit 200. Moreover, therotary actuator 118 rotates the cylinder 116 so that the cylinder 116 issubstantially horizontal and the claw portion 112 opposes to the pair ofrollers 210 and 220.

Next, the size measuring unit 200 measures the circumferential length land thickness t of the ring w. The measurement procedure will beexplained with reference to FIG. 3 to FIG. 5.

Firstly, the cylinder 228 drives upward the bracket 222 and the followerroller 220. When an upper portion of the bracket 222 is brought intoabutment with the lower limit switch 208, the cylinder 228 stops. Here,the claw portion 112 is driven forward via the rod 114 by the cylinder116 of the induction unit 100 so that the ring w is positioned outsideof the pair of rollers 210 and 220 while maintaining the substantiallyelliptic shape.

Next, upward urging by the cylinder 206 is released and the bracket 222lowers by its weight together with the follower roller 220 along therail member 224. Here, the ring w becomes prolonged substantiallyelliptic shape and released from the claw portion 112 of the sandwichingmeans 110 of the induction unit 100 and becomes tense. The sandwichingmeans 110 of the induction unit 100 is driven rearward by the cylinder116.

Subsequently, the drive roller 210 is rotated by the drive roller 214and the ring w is rotated. Here, the first displacement sensor 230transmits an output signal according to a displacement amount of thefollower roller 220 (i.e., displacement amount of the contact 232 withrespect to the highest position of the bracket 222) to the calculationmeans 231. Moreover, the temperature sensor 218 transmits an outputsignal according to the temperature of the drive roller 210 to thecalculation means 231. The calculation means 231 calculates thecircumferential length (inner circumferential length) l of the ring wfrom the diameters of the rollers 210 and 220 and the shaft-to-shaftdistance between the rollers 210 and 220 according to the output signalfrom the first displacement sensor 930. Moreover, the calculation means231 corrects the circumferential length l of the ring w according to theoutput signal from the temperature sensor 218.

This reduces the measurement error due to thermal expansion of the driveroller 210, thereby accurately measuring the circumferential length l ofthe ring w. Moreover, since the contact 232 is provided on a lineconnecting the axis of the drive roller 210 and the follower roller 220,the displacement of the follower roller 220 can be accurately detected.It should be noted that displacement of the follower roller 220 may becontinuously measured during rotation of the ring w, so as to use theamplitude average during the constant rotation of the ring was adisplacement amount. In this case, the circumferential length l of thering w can be measured more accurately.

Next, the drive motor 214 is stopped, rotation of the drive roller 210is stopped, and the thickness of the ring w tense with the weight of thebracket 222 is measured. That is, firstly, as shown in FIG. 5A, thecylinder 242 is driven to bring the inner contact 240 into abutment withthe inner circumferential surface the ring w. Here, the abutment weightis preferably about 100 g which does not deform the ring w.

Next, as shown in FIG. 5B, the second displacement sensor 260 drives theouter contact 250 into abutment with the outer circumference of the ringw. Here, the second displacement sensor 260 transmits an output signalaccording to a displacement amount of the outer contact 250 to thecalculation means 261. Moreover, the temperature sensor 218 transmits anoutput signal according to the temperature of the drive roller 210 tothe calculation means 261. According to the output signal from thesecond displacement sensor 260, the calculation means 261 measures thethickness t of the ring w. Moreover, according to the output signal fromthe temperature sensor 218, the calculation means 261 corrects thethickness t of the ring w. It should be noted that it is also possiblethat the ring w is successively rotated by a predetermined angle by thedrive roller 210 and thickness values at a plurality of positions areused to obtain an average thickness t.

Moreover, the measurement data concerning the circumferential length liand the thickness ti measured and corrected by the calculation means231, 261 are transmitted from the size measurement unit 200 to thecontrol unit 900 (arrow d1 in FIG. 11).

After measurement of the circumferential length l and the thickness t,the ring w is transported by the sandwiching means 110 of the inductionunit 100 while maintaining the substantially elliptic shape into thealigning unit 300 (arrow 3 in FIG. 1). More specifically, the clawportion 112 is driven forward by the cylinder 116 shown in FIG. 2 up tothe position outside the ring w hung over the pair of rollers 210 and220. After this, the shaft-to-shaft distance between the pair of rollers210 and 220 is reduced, thereby releasing tension and the ring w tendsto return to substantially circular shape but is regulated by the clawportion 112 in the short axis direction. Thus, the claw portion 112sandwiching the ring w in the substantially elliptic shape is drivenbackward by the cylinder 116 and the cylinder 116 is rotated downward bythe rotary actuator 118. The claw portion 112 is moved together with theframe 104 along the rail 102 upward of the plates 314 and 324 of thealigning unit 300 (virtual line in FIG. 7).

Next, rings w aligned in the horizontal direction by the aligning unit300 are aligned in a perpendicular direction. This aligning procedurewill be explained with reference to FIG. 6 to FIG. 8.

Firstly, ring w which has been transported by the sandwiching means 110of the induction unit 100 is placed on the plates 314 and 324. Then, theholding distance of the sandwiching means 110 is enlarged and the ring wtending to return to the substantially circular shape is regulated bythe regulating means 312 and 322 provided on the plates 314 and 324.Thus, as shown in FIG. 6, a pair of rings w are aligned in thehorizontal direction by the first holding means 310 and the secondholding means 320 while maintaining the substantially elliptic shape.

Next, the first convey means 340 sandwiches the ring w held by the firstholding means 310, by the arm 344. The arm 344 reduces the interval andthe ring w becomes prolonged substantially elliptic shape and releasedfrom the regulating means 312. The first moving means 340 is made toadvance by the cylinder 346 and moves the ring w onto the upper holdingmeans 331 of the perpendicular aligning means 330 (virtual line in FIG.6) while maintaining the substantially elliptic shape. Furthermore, thearm 344 increases the sandwiching interval, which regulates the ring wtending to return to the substantially circular shape in the short-axisdirection with the regulating means 333 and held as the substantiallyelliptic shape by the upper holding means 331 as shown in FIG. 8A.

Next, as shown in FIG. 8B, the first slider 337 moves along the firstinclined guide portion 335 and the perpendicular aligning means 330 ismoved to the opposing position of the second moving means 350. Thus, theperpendicular aligning means 330 is lifted up into the first inclinedguide portion 335 and the lower holding means 332 opposes to the arm 354of the second moving means 350.

The second moving means 350 sandwiches by the arm 354, the ring w heldby the second holding means 320. The arm 354 reduces its interval toprolong the substantially elliptic shape of ring w and the ring w isreleased from the regulating means 322. The second moving means 350 ismade to advance by the cylinder 356 and moves the ring w onto the lowerholding means 332 of the perpendicular aligning means 330 whilemaintaining its substantially elliptic shape. Furthermore, the arm 354enlarges the sandwiching interval, which regulates the ring w tending toreturn to the substantially circular shape, in the short-axis directionwith the regulating means 334. As shown in FIG. 8B, the ring w is heldin its substantially elliptic shape by the lower holding means 332 ofthe perpendicular aligning means 330. Thus, a pair of rings w arrangedin the horizontal direction on the first and the second holding means310 and 320 are aligned in the perpendicular direction while maintainingthe substantially elliptic shape.

Next, as shown in FIG. 8C, the second slider 338 moves along the secondinclined guide portion 336 and the perpendicular aligning means 330 ismoved to the opposing position of the convey means 360. The upper conveymean 361 and the lower convey means 362 of the convey means 360 sandwicha pair of rings w aligned in the perpendicular direction by theperpendicular aligning means 330. The arm 364 reduces its interval toprolong the substantially elliptic shape of the ring w and the ring isreleased from the regulating means 333, 334. The convey means 360 ismade to advance by the cylinder 366 and conveys the rings w aligned inthe perpendicular direction to the convey out section 370 whilemaintaining the substantially elliptic shape.

Thus, according to the aligning unit 300, only by successively movingthe rings w by the first moving means 340 and the second moving means350 onto the perpendicular aligning means 330 gradually lifted up by thefirst inclined guide portion 335, a pair of rings aligned in thehorizontal direction is aligned in the perpendicular direction.

It should be noted that it is possible to additionally provide holdingmeans other than the first and the second holding means 310 and 320,moving means according to this holding means, holding means and conveymeans in the perpendicular aligning means 330, so that three or morerings w aligned in the horizontal direction are aligned in theperpendicular direction. Moreover, as the mechanism to move theperpendicular aligning means 330, the second inclined guide portion 336and the second slider 338 may be omitted, and the first inclined guideportion 335 may be extended to extend the moving distance of the firstslider 337.

Next, the first instruction means 912 of the control unit 900 decides astorage position pi of the ring w in the first stocker 500 (s1 in FIG.11).

Moreover, the first instruction means 912 transmits “first rotationdata” according to the storage position pi to the rotation means 510 ofthe fist stocker 500 (arrow d2 in FIG. 11). The rotation means 510receives this data and rotates the first stocker 500 so that a storagechamber 502 located at the storage position pi opposes to the firstconvey unit 400.

Furthermore, the first instruction means 912 transmits “first conveydata” to the fist convey unit 400 (arrow d3 in FIG. 11). The firstconvey unit 400 receives this data and sandwiches by the sandwichingmeans 410, the rings wi aligned in a vertical direction in the conveyout section 370 of the aligning unit 300. The sandwiching means 410reduces its sandwiching interval (see FIG. 9A and FIG. 9B) and the ringwi is released from the arm 364 of the convey means 360. The ring isconveyed into the storage chamber 502 at the storage position pi of thefirst stocker 500 while maintaining the substantially elliptic shape(arrow 5 in FIG. 1). With increase of the sandwiching interval of thesandwiching means 410, the ring wi tends to return to the substantiallycircular shape but is regulated in the short-axis direction by theregulating means 504 and stored in the storage chamber 502 at thestorage position pi while maintaining the substantially elliptic shape.

Here, the timer 906 starts counting the storage time τi of the ring wiin the first stocker 500 (s2 in FIG. 11). Moreover, the memory means 908stores for each of the rings wi: the circumferential length li, thethickness ti, the storage position pi in the first stocker 500, and thestorage time τi (s3 in FIG. 11).

Furthermore, the second selection means 920 selects a ring wk whosestorage time τk exceeds a predetermined time τ (s4 in FIG. 11).Moreover, the second selection means 920 selects some of the number ofrings wk stored in the first stocker 500 and having identical size (l,t) stored in the memory means 908 and exceeding a predetermined number n(s5 in FIG. 11).

Then, the second instruction means 922 decides the convey-in position qkof the ring wk selected by the second selection means 920, in the secondstocker 700 (s6 in FIG. 11).

Moreover, the second instruction means 922 transmits “third rotationdata (part 1)” to the rotation means 510 of the first stocker 500,according to the storage position pk of the ring wk in the first stocker500 and the convey-in position qk into the second stocker 700 (arrow d4in FIG. 3); transmits “third rotation data (part 2)” to the rotationmeans 710 of the second stocker 700 (arrow d5 in FIG. 3); and transmits“third convey data” to the second convey unit 600 (arrow d6 in FIG. 2).

The rotation means 510 receives the data and rotates the first stocker500 so that the storage chamber 502 at the storage position pk opposesto the second convey unit 600. Moreover, the rotation means 710 rotatesthe second stocker 700 so that the storage chamber 702 at the convey-inposition qk opposes to the second convey unit 600. The second conveyunit 600 sandwiches the ring wk by the sandwiching means 610 and conveysit out of the storage position pk of the first stocker 500 whilemaintaining the substantially elliptic shape (arrow 6 in FIG. 1).Moreover, the second convey unit 600 sandwiches the ring wk by thesandwiching means 610 and conveys it into the storage chamber 702 at theconvey-in position qk of the second stocker 700 while maintaining thesubstantially elliptic shape (arrow 6′ in FIG. 1). With increase of thesandwiching interval of the sandwiching means 610, the ring wk tendingto return to its substantially circular shape is regulated by theregulation means 704 in the short-axis direction and is released fromthe sandwiching means 610 so as to be stored in the second stocker 700while maintaining the substantially elliptic shape.

Here, the memory means 908 stores the circumferential length li,thickness ti, the storage position pi of the ring wi in the secondstocker 700 (s7 in FIG. 11).

Subsequently, the first selection means 910 selects a plurality of ringswj to constitute a most appropriate combination according to thecircumferential length li and the thickness ti of the ring wi stored inthe memory means 908 from the first stocker 500 (s8 in FIG. 12).

Then, the first instruction means 912 transmits “second rotation data”to the rotation means 510 of the first stocker 500 according to thestorage position pj of the ring wj selected by the first selection means910 (arrow d7 in FIG. 12). The rotation means 510 receives the data androtates the fist stocker 500 so that a storage chamber 502 containingthe ring wj opposes to the second convey unit 600.

Moreover, the first instruction means 912 transmits “second convey data”to the convey unit 600 according to the storage position pj of the ringwj (arrow d8 in FIG. 12). The convey means 600 receives the data andsandwiches the ring wj by the sandwiching means 610 and the sandwichinginterval is reduced to prolong the substantially elliptic shape of thering wj so as to be released from the regulating means+ 504 (see FIG. 9Aand FIG. 9B). After this, the second convey unit 600 conveys out thering wj from the storage position pj in the first stocker 500 whilemaintaining the substantially elliptic shape (arrow 6 in FIG. 1) andconveys it to the stacking unit 800 (arrow 7 in FIG. 1).

Moreover, when it is impossible to select all the rings w constituting astacked ring in the first stocker 500, the first selection means 910selects a ring w appropriate to constitute the stacked ring R from thesecond stocker 700 according to the circumferential length lk and thethickness tk of the ring wk stored in the memory means 908 (s9 in FIG.12).

The first instruction means 912 transmits “fourth rotation data” to therotation means 710 according to the storage position qk of the ring wkselected by the first selection means, in the second stocker 700 arrowd9 in FIG. 12. The rotation means 710 receives this data and rotates thesecond stocker 700 so that the storage chamber 702 containing the ringwk opposes to the second convey means 600.

Moreover, the first instruction means 912 transmits “fourth convey data”to the second convey unit 600 according to the storage position qk ofthe ring wk (arrow d10 in FIG. 12). The second convey unit 600 receivesthis data, sandwiches the ring wk by the sandwiching means 610, andreduces the sandwiching interval to prolong the substantially ellipticshape of the ring wj and release the ring wj from the regulating means704. Then, the second convey unit 600 conveys out the ring wk whilemaintaining the substantially elliptic shape from the storage positionqj of the second stocker 700 (arrow 6″ in FIG. 1) and conveys the ringto the stacking unit 800 (arrow 7 in FIG. 1).

The stacking unit 800 stacks a plurality of rings w transported by thesecond convey unit 600 in the radius direction, so as to constitute astacked ring R and conveys the stacked ring R to the conveyer belt 850(arrow 8 in FIG. 1). Thus, the stacked ring R is conveyed out by theconveyer belt (arrow 9 in FIG. 1).

According to the ring management system of the present embodiment, withthe help of the size measurement unit 200, the first and second conveyunits 400 and 600, the first or second stocker 500 or 700, and thestacking unit 800, a series of steps including the size measurement ofthe ring w, convey, storage, and stacking can be performed withouttrouble (arrows 1 to 9 in FIG. 1). Accordingly, there is no trouble ofdifference in work quality depending on the working staffs and it ispossible to improve the production efficiency and quality of the stackedring R.

Moreover, ring wj constituting the stacked ring R is selected by thefirst selection means 910 according to the circumferential length lj andthe thickness tj (size) measured by the size measurement unit 200. Then,a ring in the storage position pj stored in the memory means 908 inassociation with the size of the ring wj is conveyed out by the secondconvey unit 600 and stacked. Accordingly, a plurality of rings wjconstituting a most appropriate combination are selected and accuratelytaken out of the first stocker 500 or the second stocker 700, therebyproducing a high-quality stacked ring R.

Furthermore, the size measurement unit 200 measures the circumferentiallength l and the thickness t of the ring w which is kept in thesubstantially elliptic shape with suppressed deformation in the radiusdirection by the restoration elasticity. This can increase the sizemeasurement accuracy.

Moreover, during a series of steps (arrows 2 to 7 in FIG. 1), the ring wis continuously kept in the substantially elliptic shape. Therefore, thering w which has been made substantially elliptic during the aboveserial steps is deformed in an unexpected direction by its restorationelasticity or scratched by contact with something. Furthermore, the ringw can be handled as “an substantially elliptic work having a constantwidth in the short-axis direction” regardless of the difference in thesize (l, t) Accordingly, holding means handling this work have commonspecifications, under which the convey means and storage means areconstituted, thereby enabling substitution and flexibillity.

Moreover, it is possible to prevent that the same ring wk is stored inthe first stocker 500 for a time exceeding a predetermined time τ or thefirst stocker contains more rings wk having the same size than apredetermined number n. This suppresses reduction of the selection width(s1 in FIG. 11) of the convey-in position pi of the ring wi in the firststocker 500 and prevents stagnation of the convey/convey-in of the ringwi (arrow 5 in FIG. 1).

Moreover, when a ring wj appropriate for constituting the stacked ring Ris not selected from the first stocker 500, a ring w is selected fromthe second stocker 700.

It should be noted that the first selection means 910 may select a ringwj conveyed out of the first stocker 500 so that the convey-in positionpi of the ring wi in the first stocker 500 opposes to the convey-outposition pj of the ring wj.

In this case, it is possible to simultaneously perform the convey-in ofthe ring wi into the convey-in position pi by the first convey unit 400and the convey-out of the ring wj from the convey-out position pj by thesecond convey unit 600, thereby increasing the production efficiency.

Moreover, the ring wj conveyed out from the first stocker 500 may beselected so that the opposing position of the convey-in position pi ofthe ring wi in the first stocker 500 is in the nearest position from theconvey-out position pj of the ring wj in the circumferential direction.

There is also a case that the ring wi conveyed into the first stocker500 and the ring wj conveyed out cannot be selected so that theconvey-in position pi of the ring wi in the first stocker 500 opposes tothe convey-out position pj of the ring wj. In this case after the ringwi is conveyed into the first stocker 500, the first stocker 500 shouldbe rotated when the ring wj is conveyed out. As the ring w conveyed outfrom the first stocker 500, the ring wj at the nearest position to theopposing position of the convey-in position pi of the ring wi isselected as described above. For this, it is possible to minimize therotation amount of the fist stocker 500 during convey-out, therebyincreasing the production efficiency of the stacked ring R.

It should be noted that in the aforementioned aligning unit 300, therings w are aligned in the perpendicular direction when the rings w aremoved from the first holding means 310 and the second holding means 320onto the upper holding means 331 and lower holding means 332 of theperpendicular aligning means 330. As another configuration, rings w maybe aligned in the perpendicular direction by arranging first holdingmeans 310 and second holding means 320 from the horizontal direction tothe perpendicular direction. Explanation will be given on aligning unit300 having the other configuration with reference to FIG. 13 to FIG. 16.Like components are denoted by like reference symbols and theirexplanations are omitted.

In the aligning unit 300 of the other configuration, the perpendicularaligning means 330, the first moving means 340, and the second movingmeans 350 are omitted. Moreover, a first guide portion 311 extends in ahorizontal direction along the arrangement direction of the firstholding means 310 and the second holding means 320 and a second guideportion 321 extends below the first guide portion 311 in parallel. Thefirst guide portion 311 has a first slider 313 moving along the firstguide portion 311. The first slider 313 is connected to the firstholding means 310. The second guide portion 321 has a second slider 323moving along the second guide portion 321. The second slider 323 isconnected to the first guide portion 311 and the second holding means320.

As shown in FIG. 13 and FIG. 14, the first holding means 310 has a guiderod 317 extending downward via a support frame (support member) 315. Theguide rod 317 can come out of the first slider 313 and by this thesupport frame 315 can be lifted up and down. Moreover, the support frame315 is urged upward by a spring member (urging means) 319. Furthermore,on the support frame 315, there is provided a cam member 318 having aninclined surface 316 gradually lowering toward the second holding means320.

As shown in FIG. 14, the second holding means 320 is connected to thesecond slider 323 via a support frame 325 through which the firstholding means 310 can move. On the support frame 325, there is provideda cam roller 326 sliding along an inclined surface 316 formed on the cammember 318.

Explanation will be given on operation of the aligning unit 300 withreference to FIG. 15 and FIG. 16. Firstly, a pair of rings w arearranged in the horizontal direction and regulated by the regulatingmeans 312 and 322 and held by the first holding means 310 and the secondholding means 320 while maintaining the substantially elliptic shape.

Next, as shown in FIG. 15A, the first slider 313 moves along the firstguide portion 311 and the first holding means 310 moves toward thesecond holding means 320. Here, the cam roller 326 of the second holdingmeans 320 slides along the inclined surface 316 formed on the cam member318 of the first holding means 310, and the support frame 315 of thefirst holding means 310 is relatively pushed downward. When the firstslider 313 moves along the fist guide portion 311, as shown in FIG. 15B,it goes below the first holding means 310 and the first holding means310 is moved immediately below the second holding means 320. Thus, thepair of rings w arranged in the horizontal direction are aligned in theperpendicular direction.

Subsequently, as shown in FIG. 15C, the second slider 323 moves alongthe second guide portion 321, and the holding means 310 and 320 aremoved to the position opposing to the convey-out means 360 (FIG. 13). Anupper holding portion 361 and a lower holding portion 362 of theconvey-out means 360 sandwich the pair of rings w held by the holdingmeans 310 and 320 while maintaining the vertical arrangement and movesthe rings w to the convey-out section 370 by the cylinder 366.

Thus, by placing rings w in the holding means 310 and 320 moved in thehorizontal direction by the first guide portion 311 and the second guideportion 321, it is possible to align the pair of rings w arranged in thehorizontal direction, in the perpendicular direction. It should be notedthat in addition to the first holding means 310 and the second holdingmeans 320, it is possible to add another holding means according to thenumber of rings w, so that three or more rings arranged in thehorizontal direction are aligned in the perpendicular direction.

1. A ring management system for management of a plurality of ringshaving elasticity in the radius direction for constituting a stackedring; the system comprising: size measurement means for measuring sizeof the ring; first convey means for moving the ring whose size has beenmeasured by the size measurement means; first storage means having aplurality of storage positions for storing rings conveyed in by thefirst convey means; second convey means for conveying out the rings fromthe first storage means; control means including: memory means forstoring for each of the rings, size measured by the size measurementmeans in association with the storage position in the first storagemeans; first selection means for selecting a ring for constituting astacked ring according to the ring size stored in the memory means;first instruction means to instruct the second convey means so as toconvey out the ring selected by the first selection means from thestorage position in the first storage means corresponding to the size ofthe ring stored by the memory means; aligning means for aligning in theperpendicular direction, a plurality of rings which have been measuredin size and aligned in the horizontal direction before being conveyedinto the first storage means by the first convey means; and the aligningmeans including: horizontal aligning means having a plurality of holdingmeans for holding a plurality of rings arranged in the horizontaldirection; perpendicular aligning means having a plurality of holdingmeans for holding a plurality of rings arranged in the perpendiculardirection; convey means for moving the perpendicular aligning means inthe aligning direction of a plurality of rings by the horizontalaligning means and lifting up so that the holding means of theperpendicular aligning means successively oppose to the holding means ofthe horizontal aligning means; moving means for successively moving aplurality of rings held by the holding means of the horizontal aligningmeans onto the holding means of the perpendicular aligning means insynchronization with the movement of the perpendicular aligning means bythe convey means; and convey-out means for conveying out the pluralityof rings held by the holding means of the perpendicular aligning meanswhile maintaining the arrangement in the perpendicular direction.
 2. Aring management system for management of a plurality of rings havingelasticity in the radius direction for constituting a stacked ring; thesystem comprising: size measurement means for measuring size of thering; first convey means for moving the ring whose size has beenmeasured by the size measurement means; first storage means having aplurality of storage positions for storing rings conveyed in by thefirst convey means; second convey means for conveying out the rings fromthe first storage means; control means including: memory means forstoring for each of the rings, size measured by the size measurementmeans in association with the storage position in the first storagemeans; first selection means for selecting a ring for constituting astacked ring according to the ring size stored in the memory means;first instruction means to instruct the second convey means so as toconvey out the ring selected by the first selection means from thestorage position in the first storage means corresponding to the size ofthe ring stored by the memory means; perpendicular aligning means foraligning in the perpendicular direction a plurality of rings aligned inthe horizontal direction before being conveyed into the first storagemeans by the first convey means after the size measurement by the sizemeasurement means; and the aligning means including: a plurality ofholding means arranged in the horizontal direction for holding aplurality of rings; moving means for successively moving one holdingmeans immediately below another holding means, so that the plurality ofholding means arranged in the horizontal direction are aligned in theperpendicular direction; and convey-out means for conveying out therings held by the plurality of holding means arranged in theperpendicular direction while maintaining the state aligned in theperpendicular direction.
 3. The ring management system according toclaim 2, wherein the convey means includes: a slider for moving oneholding means toward another holding means; a support member which canbe lifted up and down along a guide rod extending from the slider andhaving holding means at the upper portion thereof; urging means forurging the support member upward; an inclined portion provided on thesupport member and is gradually inclined downward toward the otherholding means; and a cam roller for pressing the support member againstthe urging force by the urging means via the inclined portions as theslider moves, so as to guide one holding means immediately below theother holding means.